Zig-zag sewing machine



F. GEGAUF zIG-ZAG SEWING MACHINE June 2, 1959 Filed Jun 14, 1955 Ewa 5y;

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ZIG-ZAG SEWING MACHINE Fritz Gegauf, Steckborn, Switzerland, assignor to Fritz Gegauf Aktiengesellschaft Bernina-Nhmaschinenfabrik, Steckborn, Switzerland Application June 14, 1955, Serial No. 515,490

`Claims priority, application Switzerland June 16, 1954 5 Claims. (Cl. 112-210) Zig-zag sewing machines are frequently used for bordering button holes and for producing decorative and like stitches. Means are often provided whereby the stitch length and the feed of the fabric are adjusted in such a way that the threads lie in closely adjacent rows in order to constitute a so-called bead seam.

The adjustment during machine operation of the feed of the fabric and of the stitch length, in order to produce a bead seam, necessitates a great deal of dexterity and practice of the operator. For example, if the fabric feed is the least bit too slow, the rows of threads will be arranged too closely together so that movement of the sewing work piece (fabric) may be blocked, and a thread nest may be produced, leading to a rupture of the thread or even to a breaking of the needle. If, on the contrary, the feed of the fabric is the least bit too rapid, a well formed bead seam cannot be produced, since holes and gaps will occur between the thread rows.

Usually the machine operator must re-adjust the fabric feed several times by means of the stitch length adjusting device, in order to obtain a correctly c'losed bead seam for button holes and decorative stitches. This manner f seeking of the correct stitch length frequently leads t0 damages of the work piece or fabric to be sewn, and is wearisome.

As has just been indicated, the usual devices for adjusting the feed and the stitch length do not make possible a precise adjustment with a single stroke. On the contrary, it is necessary to successively re-adjust the stitch length by means of the adjusting device until the desired stitch length is attained.

It is a prime object of the present invention to overcome the aforementioned disadvantages in adjustment of the stitch length and fabric feed. For this purpose, the sewing machine is provided with a stroke control member arranged independently of the usual lever associated with the adjustment device. This control member is adapted to limit the stroke of the lever, so that the desired stitch Ilength and fabric feed may be obtained by a single adjustment operation.

Other features and advantages of the present invention will become apparent from the following description of a preferred embodiment thereof, taken with reference to the accompanying drawing, in which:

Fig. 1 is a front elevational View of a zig-zag sewing machine provided with the stroke control member according to the invention;

Fig. 2 is a plan view illustrating on an enlarged scale the stroke control member;

Fig. 3 is a cross-section taken along lines 3-3 of Fig. 2;

Fig. 4 illustrates a portion of a bead seam partly obtained by the use of the stroke control member and partly obtained with a more rapid fabric feed when the control member is in an inoperative position;

Fig. 5 is a decorative bead seam, and

Fig. 6 shows a bead seam bordering a button hole.

In the drawing reference numeral 1 designates the hol- States Patent O low standard of a zig-zag sewing machine, and numeral 2 the handle knob of the lever 3 serving to adjust the stitch length, i.e. the fabric feed. Lever 3 may be raised and lowered within the limits of a Vertical slot or guide way 4 in standard l, and is connected with the mechanism of the stitch length adjusting device (not shown). A stroke control member 6 is pivotally mounted on the bolt portion of a screw 5, secured to the wall of standard 1 to one side of and below slot 4. Said member is formed at its end opposite the pivotal axis with a projection in the form of an abutment or a hook 6a. It will be noted that the member 6 is mounted eccentrically with respect to the bolt, so that fine adjustment is aided. The member 6 carries a handle knob 8 secured thereto by means of interengageable formations constituted by a pin 7 carried by said knob 3 and a recess 9 of the standard 1, whereby said pin may engage recess 9. Reference numeral it) designates a movable scale rotatably connected in a manner (not show) with the stitch [length adjusting 'lever 3.

The described arrangement operates as follows: It mayl be assumed that the stitch length resulting from the position of the stitch length adjusting lever 3 indicated by A in Figs. 2 and 3 should be changed in order to sew a bead seam 11 bordering a button hole (Fig. 6). For this purpose the control member 6 is brought into an intermediate operative position by swinging it into the position indicated by dot-and-dash lines in Fig. 2. Thereafter the stitch length adjusting lever 3 may be moved upwardly only as far as the point at which it bears against the hook 6a of abutment member 6. Thus in a single simple operation the stitch length adjustment lever 3 is brought into proper operative position. This adjustment of lever 3 may be effected without looking at it, as its stroke is limited by the hook portion 6a of the abutment member 6. Of course the adjusting movement of the stitch length adjustment lever 3 may be made from any starting position and at any time.

For illustration Fig. 4 shows a zig-zag seam in which the portions designated by 12 are sewn with the member 6 in inoperative position while the portions 13 are sewn as bead seams with the member 6 in the operative position shown by dot-and-dash lines in Fig. 2. For further illustration Fig. 5 shows a zig-zag bead seam 14 of varying stitch width.

It can thus be seen, that there has been provided according to the invention a mechanism for regulating the stitch length and fabric feed in sewing machines for obtaining bordered button holes and for producing decorative and like stitches, respectively. The zig-zag sewing machine has a standard which encloses said mechanism, which comprises a stitch length adjustment lever, a stroke control member located for pivotal movement on said standard, projecting means on said member, and a guideway a'long which said adjustment member may be moved and which terminates in two extreme stops against which said adjustment lever may abut when moved along said guideway, the projecting means of said control member being arranged and constructed to move in crosswise direction to said guideway and to thereby determine an intermediate stop position when said control member is moved to a location onto said guideway to thereby form a temporary stop for said stitch length adjustment lever` The control lever is arranged for pivotal movement on said standard and about an axis which extends perpendicular to the direction of said guideway, the control member being further provided with a knob facilitating movement of said control member, and respective interengageable formation on said knob and on said standard to retain said control member in two end positions relative to said guideway.

Various changes and modifications may be made without departing from the spirit and scope of the present invention and it is intended that such obvious changes and modifications be embraced by the annexed claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent, is:

1. A sewing machine having means for adjusting the stitch length and the fabric feed to thereby border button holes and produce decorative and like stitches, respectively; comprising a stitch length adjustment lever, a pivotally .supported stroke control member, projecting means on said member, and a guideway along which said adjustment lever may move to two extreme operative positions and to an intermediate operative position, respectively, said control member being swingable about its pivot onto said guideway, so that said projecting means eX- tends across the latter and determines said intermediate position of said adjustment lever.

2. A sewing machine having means for adjusting the stitch length and the fabric feed to thereby border button holes and produce decorative and like stitches, respectively; comprising a stitch length adjustment lever, a stroke control member, and a guideway along which said adjustment lever may move to two extreme operative positions and to an intermediate operative position, respectively, said control member including an abutment adapted to be moved in crosswise direction to the median part of said guideway, whereby upon movement of said control member with said abutment to said median part of said guideway said intermediate position will be determined, thereby forming a temporary stop by said abutment for said stitch length adjustment lever on its movement along said guideway.

3. In a sewing machine equipped with a standard enclosing means for adjusting the stitch length and fabric feed for bordering button holes and producing decorative and like stitches, respectively; said adjusting means comprising a stitch length adjustment lever, a stroke control member located for pivotal movement on said standard, projecting means on said member, and a guideway along which said adjustment lever may be moved to two extreme operative positions and to an intermediate operative position, respectively, said projecting means determining said intermediate position upon swinging of said control member about its pivot so that said projecting 5 means is disposed in the path of said guideway at a predetermined location thereof and forms an abutment lengthwise of said guideway for said adjustment lever, the axis about which said pivotal movement of said control member occurs extending perpendicular to the direction of said guideway.

4. ln a sewing machine according to claim 3, said control member being provided with a knob facilitating movement of said control member, and respective interengageab'le formations on said knob and on said standard to retain said control member in two end positions relative to said guideway.

5. In a sewing machine having a standard enclosing means for adjusting the stitch lengthnand the fabric feed to thereby border button holes and produce decorative and like stitches, respectively; said adjusting means comprising a stitch length adjustment lever projecting from within said standard therewithout, a stroke control member located and substantially flat on said standard, and an elongated guideway terminating in two extreme stops against which said adjustment lever may abut, when moved along said guideway, said control member being pivotally supported at one end to move with its other end, which is hook-shaped in crosswise direction of said guideway thereby determining an intermediate position in which said control member is moved to a temporary stop in said guideway, so that said stitch length adjustment tlever is impeded in its movement along said guideway.

References Cited in the le of this patent 

